1. Field of the Invention
The present invention relates to a biasing circuitry, and more particularly, to a biasing circuitry capable of adjusting a bias point of an amplifying circuit.
2. Description of the Prior Art
As technology evolves, wireless communication is an important part of human life. Various electronic devices, such as smart phones, smart wearable devices, tablets, etc., utilize wireless radio frequency (RF) systems to transmit and receive wireless signals. A low noise amplifier (LNA) and a power amplifier (PA) are necessary amplifying circuits in the wireless RF system. In order to achieve better performance (e.g., linearity), the amplifying circuit requires an appropriate bias point. A common way is to electrically connect a biasing module to the amplifying circuit, so as to utilize the biasing module for providing a bias point for the amplifying circuit.
In the prior art, the biasing module is usually formed within a die via a semiconductor process. However, due to the semiconductor process or other manufacture factors, some errors of characteristics of an internal circuit of the biasing module (e.g., the equivalent resistance or the voltage drop of the internal circuit of the biasing module) may be occurred, such that the bias point is not correct and the performance of the amplifying circuit is degraded. Furthermore, after the biasing module is formed within the die, it is not able to change the characteristics of the internal circuit of the biasing module, which is inconvenient in circuit design perspective. Therefore, it is necessary to improve the prior art.